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Test Code PBCRU Lead/Creatinine Ratio, Random, Urine

Reporting Name

Lead/Creat Ratio, Random, U

Useful For

Detecting clinically significant lead exposure

Profile Information

Test ID Reporting Name Available Separately Always Performed
PBCO Pb Conc No Yes
CDCR Creatinine Conc No Yes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10-mL urine tube (T068) or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 3 mL

Collection Instructions:

1. Collect a random urine specimen.

2. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Additional Information: High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

<5 mcg/g Creatinine

Reference values apply to all ages.

Day(s) and Time(s) Performed

Monday through Friday; 7 p.m., Saturday; 2 p.m.

CPT Code Information

83655 Lead Concentration

82570 Creatinine Concentration

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PBCRU Lead/Creat Ratio, Random, U 13466-8


Result ID Test Result Name Result LOINC Value
CDCR Creatinine Conc 2161-8
21673 Pb Conc 5676-2
21674 Pb/Creatinine Ratio 13466-8

Clinical Information

Increased urine lead concentration per gram of creatinine indicates significant lead exposure. Measurement of urine lead concentration per gram of creatinine before AND after chelation therapy has been used as an indicator of significant lead exposure. An increase in lead concentration per gram of creatinine in the post chelation specimen of up to 6X the concentration in the prechelation specimen is normal.


Blood lead is the best clinical correlate of toxicity.


For additional information, see PBBD / Lead with Demographics, Blood.

Analytic Time

1 day

NY State Approved


Method Name

PBCO: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CDCR: Enzymatic Colorimetric Assay

Test Classification

See Individual Test IDs